Regarding railcar bogies, to deal with wear and the like of wheels, a downward load (wheel load) applied to each wheel is adjusted in some cases in such a manner that a thin liner (spacer) is sandwiched between an axle receiver and a spring receiving seat located at an upper side of the axle receiver and supporting an axle spring. PTL 1 proposes a wheel load measuring device that measures the wheel load by utilizing the liner. The liner of the wheel load measuring device is configured by sandwiching a pressure sensor between two thin adjustment plates and calculates the wheel load based on an output from the pressure sensor. PTL 1 describes that a thickness of the pressure sensor is several tens to a hundred and several tens of micrometers, and a thickness of the entire liner is about 1 to 3 mm.